In medical applications an aspiration device is one which applies suction or partial vacuum to draw a fluid or sample into a syringe or into an attached needle lumen. Such devices are particularly useful for aspirating fluid and blood, and for securing soft tissue samples from the thyroid, liver, kidney and spleen, as well as from neoplastic and non-neoplastic pulmonary lesions, hepatic tumors, carcinomas of the breast, and palpable subcutaneous masses and nodes for histologic and cytologic examination.
At the present time, biopsy specimens are obtained by surgical excision or by needle biopsy. In the latter, soft tissue and aspirated specimens are obtained by any of several techniques, all of which involve applying negative pressure to the needle to obtain or assist in severing the specimen. Since most biopsies are performed by one person, certain device limitations have brought about procedural disadvantages with prior art techniques. These disadvantages are eliminated when using the device of the present invention.
The simplest and most widely used prior art aspirating device is a conventional, plastic hypodermic syringe of the type having a hollow needle opening into a syringe barrel and a plunger for varying the volume and pressure inside the syringe barrel. In use, negative pressure is applied by drawing back on the plunger. This requires two hands, one to hold the syringe barrel and one to withdraw the plunger.
The main disadvantage to using a conventional syringe as an aspirating device to assist in biopsy, is a necessity to have one hand free to do something other than operate the device. For example, when doing fine needle aspiration of a nodule, it is necessary to secure or immobilize the mass being sampled. This is usually done with two fingers of one hand, while making multiple sticks with the needle and at the same time applying intermittent or controlled suction with the other hand. Other procedures, such as biopsy of the liver or kidneys, are preferably done with the suction applied just prior to retracting the needle from the organ. When performed by one person, the procedure becomes a slow and somewhat cumbersome two-handed technique.
In fluoroscopic, ultrasound or CT scan aided biopsy, it is often necessary for a second person to assist with the procedure. This is sometimes accomplished by the addition of a flexible tube connecting the needle to the syringe barrel. The purpose of the tube extension is to allow one person to apply vacuum while the other controls the positioning of the needle for biopsy. Having suction applied by someone other than the person controlling the needle does not lend this approach to the general field of fine needle aspiration biopsy since the person applying the suction cannot easily determine when to apply it. In addition, this two-person approach not only adds to the professional component cost of the procedure, but it is also technically less effective since it generally requires more time than other procedures.
Prior medical aspiration devices suffer disadvantages of being structurally complicated and cumbersome thereby precluding convenient single-hand use. (See for example U.S. Pat. No. 3,819,091, issued to Hollender, June 25, 1974; U.S. Pat. No. 2,863,452 issued to Ogle, Dec. 9, 1958; and U.S. Pat. No. 2,472,116 issued to Maynes, June 7, 1949.